The role of innate immunity in dementia with Lewy bodies (DLB) has been little studied. We investigated the levels in cerebrospinal fluid (CSF) of glial proteinsYKL-40, soluble TREM2 (sTREM2) and progranulin in DLB and their relationship with Alzheimer's disease (AD) biomarkers. We included patients with DLB (n = 37), prodromal DLB (prodDLB, n= 23), AD dementia (n = 50), prodromal AD (prodAD, n= 53), and cognitively normal subjects (CN, n= 44).We measured levels ofYKL-40, sTREM2, progranulin, A beta(1-42), total tau (t-tau) and phosphorylated tau (p-tau) in CSF. We stratified the group DLB according to the ratio t-tau/A beta(1-42 ) (>= 0.52, indicative of AD pathology) and the A/T classification. YKL-40, sTREM2 and progranulin levels did not differ between DLB groups and CN.YKL-40 levels were higher in AD and prodAD compared to CN and to DLB and prodDLB. Patients with DLB with a CSF profile suggestive of AD copathology had higher levels of YKL-40, but not sTREM2 or PGRN, than those without. T+ DLB patients had also higherYKL-40 levels than T-. Of these glial markers, onlyYKL-40 correlated with t-tau and p-tau in DLB and in prodDLB. In contrast, in prodAD, sTREM2 and PGRN also correlated with t-tau and p-tau. In conclusion, sTREM2 and PGRN are not increased in the CSF of DLB patients. YKL-40 is only increased in DLB patients with an AD biomarker profile, suggesting that the increase is driven by AD-related neurodegeneration. These data suggest a differential glial activation between DLB and AD.